<span>"They have different numbers of neutrons and different mass numbers. Remember mass number is protons plus neutrons. The number of protons for an element will never change, however the number of neutrons can." I took the test, its D</span>
Answer:
The volume of the gas at given temperature is 
Explanation:
= initial pressure of gas = 1 atm
= initial temperature of gas = 
= initial volume of gas = 
(
, 1 mL = 0.001 L)
..[1]
= final pressure of gas = 2.1 atm
= final temperature of gas = 
= final volume of gas = ?
..[2]
By dividing [1] and [2] we get combined gas equation :,
Now put all the given values in the above equation, we get:
The volume of the gas at given temperature is
A streak is <span>a long, thin line or mark of a different substance or color from its surroundings.</span>
Answer:
As we read from left to right across the periodic table atomic numbers are increased by one each of element.
Explanation:
As we move from left to right across the periodic table the atomic number is increased by one and the number of valance electron in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.
Explanation:
To balance the reactions given, we must understand that the principle to follow is the law of conservation of matter.
Based on this premise, the number of moles of species on the reactant and product side must be the same;
Li + Br₂ → LiBr
Put a,b and c as the coefficient of each species
aLi + bBr₂ → cLiBr
balancing Li;
a = c
balancing Br;
2b = c
let a = 1;
c = 1
b = 
or a = 2, b = 1 , c = 2
2Li + Br₂ → 2LiBr
P + Cl₂ → PCl₃
Using the same method;
aP + bCl₂ → cPCl₃
balancing P;
a = c
balancing Cl;
2b = 3c
let a = 1;
c = 1
b = 
or
a = 2, b = 3, c = 2
2P + 3Cl₂ → 2PCl₃
iii,
H₂ + SO₂ → H₂S + H₂O
use coefficients a,b,c and d;
aH₂ + bSO₂ → cH₂S + dH₂O
balancing H;
2a = 2c + 2d
balancing S;
b = c
balancing O
2b = d
let b = 1,
c = 1
d = 2
a = 3
3H₂ + SO₂ → H₂S + 2H₂O
